Pyoderma Gangrenosum: A Paraneoplastic Syndrome Associated with Occult Colorectal Malignancy? Report of A Case and Review of Literature


Khalid Ahmed, Sudarsanam Raman, Nimalan Pathma-Nathan

Introduction: Pyoderma gangrenosum (PG) is an uncommon sterile inflammatory neutrophilic dermatosis. Approximately 50% of PG patients have associated inflammatory bowel disease, rheumatic disorders or malignancies. Literature search reported only 2 cases of PG in association with colorectal cancer (CRC). Case Report: A 74-year-old patient presented to the emergency department with central abdominal pain and vomiting for 24 hours. Recently, the patient was worked up for iron deficiency anemia and was due to have colonoscopy. She was also discovered to have multiple skin lesions on her left hand, which were ulcerated, erythematous, indurated, and thick with scaly plaque. Initially the differential diagnosis included: neutrophilic dermatosis, atypical mycoblastosis or mycosis. Skin biopsy revealed PG. The skin lesion did not respond to high-dose systemic steroids. Two months later during presentation to the emergency department with abdominal pain, abdominal and pelvic CT showed proximal sigmoid colon mass with nodular extension probably involving adjacent small bowel loops but no liver metastasis. Colonoscopy showed stenosing sigmoid mass, which was confirmed by biopsy to be adenocarcinoma. Laparotomy with resection of the sigmoid, upper part of the rectum, and a short segment of the involved small bowel was performed. Histology confirmed adenocarcinoma of the sigmoid (T4N0Mx). The skin lesions healed spontaneously following surgery. Conclusion: Early treatment of CRC can enhance the outcome of patients with PG, which may point toward a related pathological process. Furthermore, PG may be an important predictor of CRC. We advise on detailed gastrointestinal tract GIT investigation for unresponsive PG.